What to make a knife sharpener. Knife sharpener - a necessary tool on the farm

Interest in making do-it-yourself knife sharpeners arises for a reason. The consumer qualities of hand cutting tools are increasing due to the use of modern materials and technologies for the manufacture of the blade and precise factory sharpening. At the same time, the price of the product is also growing, but it is becoming easier to spoil a rather expensive thing with a primitive sharpening. Therefore, various household tools for sharpening knives are needed not only for convenience. To understand why a knife sharpener is still needed and how to make it correctly, you will have to start with the ideology and evolution of the knife.

Why do you need a sharpener

A living relic of our days is a Finnish hunting knife. Not a bandit finca, sometimes of a bizarre shape, but a Finnish-type hunting knife, on the left in fig. Traditional hunting knives (center and left) are similar in shape, but the difference between them is very large.

A Finnish knife blade is forged from blast iron, which can be smelted right in your yard from swamp ore in a blast furnace, without resorting to blast furnaces, puddling, and other methods of converting cast iron into iron and steel. The viscosity of the blast iron is excellent, it is very difficult to break a blade from it. But the hardness is also low, somewhere HRS55, the knife gets dull pretty quickly. Finnish hunters did not care about this: a blade of such hardness can be directed (sharpened) with a beating on many natural stones, and there were always enough ironed moraine boulders in Fennoscandia.

They sharpen a knife with a chop in about the same way as they beat off a scythe, only the touchstone is motionless, and the blade is moved. First, it is pulled along the donkey with its butt away from itself, then it is turned over and pulled with its butt towards itself. The position of the cutting edge (RC) on the donkey is always dragging; fast movements: shirk-shirk! At each movement, you need to keep the contact patch of the blade with the touchstone (see below), but the requirements for maintaining the angle of inclination are not so strict. Learning to sharpen a knife with a chop is not very difficult, and with some skill, you can direct a smoothly running profile onto the blade, see below. However, the Finnish knife is in general a dead end for the evolution of cutting tools, which survived in special natural conditions.

A good knife was never cheap, and in an extreme situation, the durability of the blade, combined with the toughness of the blade, became vital circumstances. Therefore, even in antiquity, knife blades learned to harden from the surface and cement: the core remained viscous, not brittle, and a hard hot crust formed on it outside, see the trace. rice.:

It is still possible to direct a knife with a cemented blade with a chop, but a skill is needed that is not given to everyone. And the abrasive is already needed from a special kind of stone - Grünstein lithographic slate. There is little of it in nature; Grunstein is still considered a strategic raw material. There is no artificial grunstein and is not expected. To spoil the cemented knife with an inept beating is as easy as shelling pears - a little somewhere the cementation crust is pulled off to raw metal (you can't see this by eye), the knife will only have to be thrown away, the blade will immediately become blunt and crumble.

Note: if you have an old scythe donkey of a slightly greenish color lying around somewhere, do not throw it away, it is a valuable rarity.

Household workers do not need such stamina and toughness as hunting and marching ones, and they should cost a lot less. As a result, special steels and powder metallurgy are widely used in the production of household goods. The blade of the "eternal" kitchen knife is structured like a rodent's chisel: longitudinal layers, the hardness of which falls from the core outward. In any case, the knife has to be sharpened less often, but the beating is unambiguously excluded - the blade from it immediately crumbles.

How do you sharpen a knife?

For these reasons, a push-pull sharpening technology has long been invented:

The blade is pushed on the touchstone away from you with a twist, holding the butt towards you, the position of the RK is oncoming (scraping);
Then, without removing the blade from the touchstone, pull it with the butt towards you with a turn in the opposite direction, the position of the RK is dragging;
The blade is turned over and paragraphs are repeated. 1 and 2;
Pp. 1-3 are repeated, in each cycle, reducing the pressure, until the burr formed on the RC comes to naught (does not merge).

Note: when they say or write "the burr will go away", etc., this is not true. The metalworkers have the slang word "zausyavka"; for electricians - "off". But in Russian, the burr and the switch are masculine.

Push-pull sharpening protects the blade, but requires high skill from the operator, because a number of conditions must be observed continuously and precisely during the sharpening process, see also fig. below:

Maintain the angle of inclination of the blade to the touchstone, smoothly changing it in accordance with the curvature of the RK.
Make sure that the tangent to the generatrix of the blade and the transverse axis of the contact spot between the RK and the donkey coincide.
Also make sure that the axis of the contact patch is always perpendicular to the longitudinal axis of the stone.
Smoothly change the pressure on the blade as the area of the contact patch changes.

It is very difficult to comply with all these conditions at the same time, completely symmetrically on the forward and reverse travel of the blade along the touchstone, and a modern knife, as mentioned above, can be damaged by improper sharpening. Any household device for sharpening knives is just intended to save the grinder from continuous control of at least part of the specified conditions.

Note: for successful push-pull sharpening, the length of the donkey (see below) must be at least 2 lengths of the knife blade from the handle to the tip.

Sharpening profiles

The blade profile of a knife is linked to the material properties and structure of the blade, as well as the properties of the materials for which the tool is designed. Sharpening with a simple blunt wedge (pos. 1 in the figure) gives a stable but coarse blade: the cutting resistance is high, and the knife tears rather viscous materials. A sharp wedge (pos. 2) quickly dulls or crumbles; on viscous and / or fibrous materials, the cutting resistance may be greater than a blunt wedge due to the friction of the cut off blade.

Ideal in all respects is the ogival (smoothly running off) profile, pos. 3. Experts still argue which generator is better - involute, hyperbole or exponential. But one thing is indisputable - it is difficult and expensive to make an ogival blade in production conditions, and it is impossible to direct it yourself. Therefore, ogival-sharpened knives are used only in special equipment, for example. microtomes - biological devices for obtaining the finest tissue sections.

For disposable blades, e.g. safety razor blades, faceted sharpening is used, pos. 4, i.e. The ogive generator, as mathematicians say, is approximated by line segments. The number of sharpening edges is indicated in the certificate or on the manufacturer's website. For thick coarse bristles, 3-4-sided is better; for delicate hair not on the face - 8-sided. 6-sided is considered universal.

Angle α

The sharpening angle is always given in half the value of α, since many tools, such as bayonet knives, are sharpened to one side. For knives for various purposes, the angle α is maintained in the next. limits:

10-15 degrees - medical scalpels, straight razors, art carving knives.
15-20 degrees - confectionery (for cakes) and vegetable knives.
20-25 degrees - bread and sirloin knives.
25-30 degrees - hunting, hiking, survival knives.
30-35 degrees - general purpose household knives.
35-40 degrees - carpentry tools, shoe knives, axes.

One and a half

Sharpening of knives, except for special ones, is done almost exclusively with a one-and-a-half profile, on the left in Fig. One-and-a-half sharpening is so named because the flat edge of the blade (escapement) is formed during the manufacturing of the blade and cannot be sharpened. In fact, guiding a one-and-a-half-sharpened knife is no more difficult than sharpening with a simple wedge. One and a half sharpening is optimal for a knife that works with a variety of materials, and making a sharpener for one and a half sharpened knives is much easier than for sharpening a faceted one.

In the center and on the right in Fig. shows the stages of sharpening the blade and the numbers of abrasives used on them. The abrasive number corresponds to the number of its grains per 1 sq. mm surface. The fine-tuning stage has some features:

Hunting and camping knives are not supplied. This makes it easier to cut hard (eg bones) with a broach (with filing). In addition, if you accidentally cut yourself, then a slightly lacerated wound stops bleeding faster, heals more easily and there is less danger of infection entering it.
Blades of dangerous razors, knives for shoemakers and for artistic carving after an abrasive are brought to mirror smoothness on a leather donkey with GOI paste.
Guiding and finishing the blades of kitchen knives can be done in one operation with abrasive No. 800-1100.

Touchstone

A homemade knife sharpener will be much more convenient and more accurate if you do not buy a touchstone for it, but make a piece of a square pipe 200-300 mm long (on the left in the figure below) or a wooden block from a piece.

The edges of the base are pasted over with an emery cloth acc. numbers. Glue is a stationery glue stick. The advantages of a skin based donkey are obvious:

Much cheaper than an emery bar.
Can be made in 4 abrasive numbers, whereas emery stones are maximum 2-sided.
Wear (development) of the abrasive is possible no more than the thickness of the abrasive layer of the skin; waviness of the RK due to the rotation of the whetstone on the sharpener rod (see below) is also no more than this value.
As a result, the error of the sharpening angle from the development and rotation of the donkey does not exceed fractions of a degree.
The touchstone from the pipe can be put on the threaded rod (center in the figure), which makes it quicker and easier to change the abrasive.
A touchstone from a pipe or a wooden bar is held in any clamps under an emery bar no worse than the last one, on the right in Fig.

Knife sharpeners

The simplest manual knife sharpener is a corner frame in which a whetstone is clamped, pos. 1 per next. rice. The same type of "firm" is on sale, and this is marketing, so marketing: they want up to $ 50 or more for a plastic board with inclined nests for donkeys. Whetstones - non-standard sizes; ordinary ones do not fit into holes. Worked out - you need to buy original ones. You understand the price. And all the convenience - when sharpening the blade, it is still easier to keep the blade strictly vertical than to maintain the angle of its inclination.

The use of the simplest knife sharpener can be further simplified to a complete absence of the need for skills, if it is supplemented with a sliding shoe with a magnetic knife holder, pos. 2. The order of sharpening in this case is the following:

The knife is held with the right hand by the handle, turning in the direction of travel according to the curvature of the blade;
With the fingers of the left hand, except for the thumb, they press the shoe to the donkey;
The thumb of the left hand is pressed on the butt of the blade, pressing the RK to the abrasive.

In this case, the function of maintaining the angle of inclination is removed from the operator, and the rest are distributed over 2 hands. In this case, the skill of sharpening with your own hands is developed immediately, but a holder is needed that firmly holds the knife and at the same time allows it to slide on its surface. This can be done from the magnets of the drive of the carriage of the read-write heads from an unusable HDD (hard drive). The "screw" carriage drive magnets are niobium, thin, flat, even and very strong (shown by red arrows in pos. 3). They are glued with DIFFERENT poles on a steel strip, the force of attraction of the blade will then double. And to ensure sliding, the holder is covered with a fluoroplastic film 0.05-0.07 mm thick. PET from bottles will also work, but it is thicker and the attraction will be weaker. Polyethylene is not good, it will wipe right away.

Note: remember this holder, we will still need it.

LM

It does not require any special skills and the use of a manual knife sharpener of the Lansky-Metabo type, pos. 1 in fig. A diagram of its device is given in pos. 2, and the procedure for use is in pos. 3. The disadvantage of the Lansky-Metabo sharpener is the instability of the sharpening angle along the length of the blade: a rod with a donkey is driven along it. In this case, the offset of the touch point is continuously changing, because it describes an arc of a circle, and a blade of a different configuration. Corresponding "Floats" and the angle. Therefore, the Lansky-Metabo sharpener is used primarily for sharpening camping and hunting knives with a relatively short blade.

However, this disadvantage can be turned into dignity if the blade is clamped in the terminals with the root part A (at the handle) and with the tip slightly turned away from itself, pos. 4. Then, at the root of the blade, the sharpening angle will be the greatest, which is optimal for processing hard materials or using the knife as a cleaver. So after all, they work in such cases, so that the outer arm of the arm-blade lever is shorter.

Towards the middle of blade B, the sharpening angle will smoothly decrease and reach a minimum at the bend of its generatrix B1, which is convenient for fine work. Then, the angle will increase again towards tip B, which will make the tip more resistant when drilling, slotting / impacting and punching (piercing).

Note: Another disadvantage of the Lansky-Metabo sharpener is the difficulty of execution in the tabletop version. But this drawback, as they say, is fake, see pos. 5.

Part drawings of the original Lansky-Metabo sharpener are shown in fig. The numbers at the windows for the bar (guide) correspond to the FULL sharpening angles.

On the trail. rice. an assembly drawing of the clamp is given, and then - drawings and dimensions of Lansky-Metabo terminals made of a 90x90x6 mm angle. The author of the development is hiding under the pseudonym Serjant. This is undoubtedly a matter of his modesty. But, by the way, in production, technological innovations that make it possible to use standard profiles for the manufacture of shaped parts are sometimes valued more expensive than serious inventions.

Note: on the trail. rice. an assembly drawing of the Serjant sharpener is given. About the inconvenience of fastening in a vice - see above.

Knife sharpening machine

The most advanced household manual sharpener today is the Apex type knife sharpener. Its appearance, device diagrams and the order of use are shown in Fig. Apex can be made to a continuously variable sharpening angle (pos. 2) or to fixed angles like Lansky-Metabo (pos. 3). Nominally, they work on Apex like on Lansky-Metabo (pos. 4), but other options are possible for more accurate sharpening, see below.

Homemade version of Apex knife sharpener - Skomorokh knife sharpener

In 2016, in Runet, it made a noise, perhaps no less than the bubafony stove, the desktop modification of Ivan Skomorokhov's Apex, see fig. on right.

Sharpeners Skomorokh are much simpler than a prototype and are in no way inferior to it in functionality.

How to make a Skomorokh knife sharpener, see the video:

Not only knives ...

The original Apex sharpener is not very suitable for sharpening carpentry tools - chisels, iron planes. The Apex's sharpening angle floats for the same reasons as the Lansky-Metabo. Meanwhile, if the angle of sharpening of the chisel along the width of the blade "walks" by more than 1-1.5 degrees, then the tool strives to go sideways, crawl out or go deep into the solid wood along its fibers. It is very difficult to precisely and accurately select a groove for a tenon / ridge with such a chisel.

For sharpening carpentry tools, there are special devices, about which a special conversation is needed. Homemade products like a roller trolley sharpener, see fig. on the right, rather curiosities: not to mention the complexity, they require a stone or steel table, and, most importantly, they do not guarantee against the distortion of the blade on the donkey, which leads to the same undesirable result.

Meanwhile, 2-3 years ago, in one of the Chinese magazines on technical creativity, there was a glimpse of the Apex's refinement for sharpening, not inferior to that of a factory electric semiautomatic sharpening machine. The alteration is not difficult, see fig: the bar is set horizontally in level and the horizon of the bar is held along it, while sharpening. Within the angle of rotation of the rod in the horizontal plane 10-12 degrees to the right-to the left, the error of the sharpening angle is less than 1 degree. If the extension of the point of contact is from 250 mm, it is possible to sharpen chisels and glands of planers up to 120 mm wide.

In this operating mode, a (theoretically) zero sharpening angle error can be achieved by keeping the bar stationary, and moving the knife held by the magnetic holder, see above. Thus, it is possible to sharpen the glands of shaped planers, if you put a round in cross section, semicircular, elliptical or segmental touchstone in the clamps. The main thing is that the touch spot is always point-like.

... but also scissors

Another refinement of the Apex sharpener for sharpening scissors (also a necessary business on the farm) is shown in Fig. on right. Total work - a couple of corner pieces or galvanized scraps and 4 additional holes in the sharpener table. About the process of making do-it-yourself attachments for sharpening scissors for the Skomorokh sharpener, see next. video:

Video: sharpening scissors, attachment to the Skomorokh sharpener

Finally, more about scissors

Check for loose hinge before grabbing poorly cutting scissors into the sharpener. Spread the scissors apart and look at them from the side. See, the tip is wrapped with a screw towards each other? Therefore, the scissors cut: the point of contact of the blades during cutting shifts from the roots to the ends. And therefore it is difficult to cut with scissors with the left hand: the turning of the ends is designed for the kinematics of the right. And if the hinge of the scissors is loose, the blades will go away from each other and will not even cope with the paper. In this case, you just need to tighten the riveted hinge with a hammer, and with a screw - with a screwdriver.

In households, it is quite often necessary to use cutting, sawing and planing tools. In the process of work, they lose their sharpness, and the blade needs to be restored to its original properties.

Giving the tools to the workshops to be sharpened is a reasonable option, but in order not to waste money once again, you can make a tool for sharpening knives with your own hands.

General information about sharpening knives

The purpose of any type of knife sharpening is to keep the blade sharp. And the most important factor that affects long-term and efficient operation is the size of the sharpening angle. The practicality of such a parameter is well appreciated in the course of work. If you look objectively, you will notice that with a smaller value of the angle, the knife blade results in a sharper one. But with such an action, it turns out that the period of improved cutting qualities is not very long, that is, it dulls faster. The sharper the knife blade becomes during the sharpening process, the more quickly it will become dull. Based on this pattern, one can conclude that the angle must be selected correctly and the value must be falsely observed along the entire length of the edge evenly.

It should be noted that only those types of blades that have a certain degree of hardening are subject to sharpening. If the hardness of steel on the cutting parts exceeds 55 HRC, then it cannot be sharpened with any improvised tool.

The golden rule for sharpening knives is that the angle of sharpening of the cutting edge remains constant throughout its length.

To achieve this, you need professionalism, skills and special equipment that will allow you to hold the tool in your hands, maintaining a given angle of inclination of each cutting edge.

In this case, you can take care of buying a special device, but such products are usually expensive, so you can try to make it yourself. For more information on how to make such a device at home, read below.

Video "Homemade design of a simple knife sharpener"

Features of using the device

Of course, a simple whetstone is fine for sharpening a knife or the cutting edge of a planer. But its quality will not be the best. To ensure uniform removal of the metal layer and accuracy of processing, it is necessary to use special sharpening devices.

The advantage of such a product is not only its ease of use, but also factors such as:

The ability to fix the blades, which is reliable enough and does not overload. a properly designed device does not allow metal damage during operation.
Possibility of setting the bar at a certain angle. Due to this, when the cutting edge moves, the angle value will not change.
Variation of setting different sharpening angles. With this functionality, it is possible to process various tools, even sharpening knives with a stepped structure.

Materials and tools required for the device

To perform a simple and quite solid device, you need to take care of the preparation of the following blanks and tools:

plywood or a small laminated chipboard sheet;
steel studs with a diameter of 8 mm (the thread on it must be cut along the entire length);
textolite or ebonite bar (alternatively, you can replace it with hard wood - beech, oak, etc.);
aluminum plate (with a thickness of at least 5 mm);
fasteners - bolts, nuts (wing nuts);
a neodymium magnet (found on an old computer HDD).

Drawings of a tool for sharpening knives with your own hands

After preparing and completing with materials, you can begin the process of assembling the fixture. First of all, we take plywood for use as a bed, which should rest on the fixing legs at certain angles in the range from 15 to 20 degrees. After that, a hairpin prepared by us is twisted into the lower part, its length should be about 35-40 cm. To make the landing thread more durable, you can use glue or sealant.

We fasten the aluminum plate in the center of the installed plywood. Before fastening it, it is necessary to make a groove that will correspond in size to the diameter of the fixing bolts. It is worth noting that we use an aluminum plate as this will help prevent damage to the steel blade of the knife.

After that, we proceed to the manufacture of a lever that will allow you to fix the emery on the device. To assemble it, we use the rest of the stud. Then we take two textolite (or wooden) bars and, by sawing out, make holders for the lever. On one side, the stops should be secured with a wing nut.

It is optimal to provide for the presence of a spring-loaded block near the handle, which will allow you to quickly change the emery stone.

As the main elements, you can use blanks from homemade bars - we glue sheets of sandpaper to the aluminum plate, while the grain size should be different. Such a device can be easily fixed in the lever.

The main design feature is the presence of a hinge with a double degree of freedom. Such a device can be easily assembled by using identical pieces of textolite for this. One of them should be screwed onto the thread of the vertical stud, and used as a horizontal pivot axis and a height adjuster for the lever support (this is necessary to set the grinding angle).

The function of the second bar, which has a horizontal hole for the lever, is that it must be screwed onto the first.

Thanks to this, it is possible to provide a free type of movement of the entire lever structure vertically.

The knives are clamped by a plate, or fixed to the surface of a neodymium magnet. Removing the first layer with coarse types of abrasive, the blade must be securely fixed.

If it is necessary to perform fine-tuning, then you can install the blade on a magnet and perform the sharpening operation with little effort. The horseshoe of the magnets should be recessed flush with the countertop and grounded with epoxy glue.

Making a homemade knife sharpening device can be considered complete. It is enough to set the desired angle, sharpen the edge slowly with a smooth movement along the entire length of the blade.

Video "DIY knife sharpener"

Electric knife sharpener

An electric sharpener will not only speed up the work, but also make it possible to obtain high-quality concave edge profiles on the blades, the so-called dolly sharpening. It is impossible to achieve such forms by means of a linear bar; therefore, these types of devices are not interchangeable, but complementary devices.

It is noteworthy that a person, working on a manual sharpening device, a person himself controls the speed and intensity of the processes performed, while the emery wheel has a constantly high rotation speed, which can negatively affect the state of the knife.

When rubbed, the metal surface is very hot, which results in "tempering" of the hardening of the steel. The material loses many properties, it becomes less hard, which leads to grinding and the appearance of torn edges. Another problem with a loose knife is the rapid loss of sharpness. In this regard, it is necessary to work carefully on an electronic grinder, bringing the sharpening blade to the abrasive for short periods of time and taking frequent breaks in order for the knife to cool down.

Working in such modes, it is quite problematic to maintain constant angles, so the tool needs reliable fixation during such processing.

It is quite simple to implement the design of such a device. In the direction of the rotating axis on the emery there are guides along which the carriages with knives move. The angles are maintained mechanically and the forces are determined directly by the operator.

This type of device is quite simple to do with your own hands - there is no need to perform precise work to process metal parts. For the manufacture of guides, foot material is actually used.

On the workbench, near the sharpener, guides are attached, with the help of which it is possible to change the distance from the knife stops to the abrasive. This distance affects the angle of sharpening. On the vertical rod, there must be up and down freewheel adjusters that have strong types of fixing the current positions.

The knife blade should be held horizontally, with pressure against the thrust element. The force in contact with the emery must be adjusted directly in the process. Processing must be carried out symmetrically, it is enough just to change the sides of the knife and sharpen them at the same angles.

The use of this method can only be suitable for processing the classic type of knives. Kitchen, hunting, camping and other types of cutting planes of various tools require a slightly different approach.

A common type of design for sharpening knives - "Jointer"

For such a device, it is necessary to use a specialized emery, with an end-type working surface. The guide for the carriage is placed at the bottom so that it is located away from the rotating axis. This is due to the fact that in this part of the abrasive wheel, its work is considered the most effective. The guides with cutting elements are moved manually, the clamps are provided by the tool's own weight.

A drawing of each structural unit is shown in the image.

This type of machine was used at the beginning of the last century, and for all the time the technology of its operation has remained unchanged. Due to the simplicity of this device, it is easy to make it for your home workshop. Any components made of metal, plastic, wood are suitable for this.

By replacing the cutting element on the jointer, you can sharpen the blades of ice axes, the main thing is to maintain the correct angle, which should be flatter. Scissor sharpening devices work on the same principle.

To sharpen a chisel and a knife from a planer, you can also use an electronic emery board and locking carriages. But these types of tools are compact and can be sharpened with a mechanical device.

There are equivalent ways - along the edges, and across. In terms of quality, the processing is practically identical, in this connection it is impossible therefore it is impossible to preferentially distinguish a specific type of device.

For factory products, transverse dressing of the blades is assumed.

By a similar principle, thick plywood is taken from which the card is made. As a guide, you can use any rollers, preferably more than two. By moving the machine over the surface of the emery, the chisel blade is given a perfect shape.

If serious types of sharpening are not required, simpler devices are also suitable for small edits.

Fix the bars with the required angles of inclination to the chisel. Put emery and a piece of glass next to them. Apply a soap solution to the glass surface.

You will be pleasantly surprised by the effectiveness of such devices.

For transverse sharpening, it is worth making a simpler device, where the guide element is also used as a support. A blade is mounted on the movable part in a vertical manner. The only drawback of this is the fixed angle, which is set during the manufacturing process.

But, in comparison with a knife, the deviations from ideals that have arisen are not so critical.

This type of attachment can be used to sharpen planer knives. But due to the wide size of the blades, the process is somewhat more complicated. In this regard, you can use an electric grinder, which has an end working surface.

Stops are made of wooden blocks. It is important to consider the possibility of changing the angles. The clamps are provided by the operator, while a semicircular sharpening can be performed, which is very indispensable for carpenters.

Naturally, this device is convenient to use for sharpening the edges of the chisels. Given the high performance indicator, you will be able to repair tools with even a large number of chipping.

Now you know how you can create a homemade sharpener to perform all the necessary operations for sharpening knives at home.

Video "Attachment for sharpening various types of knives"

Almost every DIYer has cutting tools available. Over time, the cutting edges lose their former sharpness, and work with such a product becomes unbearable. There are two options for solving this problem: to give a tool for sharpening and pay a lot of money, or to assemble a device for sharpening knives yourself and sharpen the products with your own hands.

Blade blunt reasons

The bluntness of the blade can be explained as follows. During cutting, the blade is exposed to the smallest abrasive particles, be it fruits or vegetables. The cutting edge of the blade gradually wears away and the knife becomes dull. Another reason is keeping the blade at a certain angle when cutting.

On some areas of the blade, the load increases, and increased wear occurs.

There are types of knives that cannot be sharpened on their own due to the embossed blades. Also, knives made of ceramics cannot be sharpened. But, as a rule, the quality of steel in such products is high, and they rarely become blunt. There are some poor quality knives and they have to be sharpened very often. As practice shows, if the steel is of poor quality, then sharpening will solve the problem for a while, and then the blade will become dull again.

You will need abrasive wheels to sharpen your knives. If it is not possible to purchase ready-made circles, then you can make them yourself using wooden blocks and sandpaper of different grain sizes.

The standard sharpening angle is 20 - 30 degrees. It is quite difficult to maintain the angle during sharpening, and therefore it is necessary to make a simple knife sharpener, in which it is not necessary to maintain the optimal angle. The basic rule in this process is to maintain a precisely defined constant angle. Strength is not required here. The main thing is that the bar and the blade meet at a certain angle. This is the basic rule of sharpening technique.

Major mistakes

As it may seem at first glance, sharpening is simple, but if you delve into the process itself, you will notice a fairly large number of different nuances. Most people make trivial mistakes when sharpening knives, which leads to uneven sharpening or damage to the knife. Common mistakes when sharpening:

The cutting edge has not been sharpened... As a result, small burrs form on the sides, which temporarily sharpen the blade, and after a short time with the knife, the blade becomes dull again. To prevent this problem, you should carefully sharpen both edges, and then, as you sharpen, use sandpaper or a wheel of different grain sizes.
The presence of paint, oil, dirt on the tip... The bottom line is that when turning, fat, dirt, oil and other components are mixed with grinding abrasives and lead to scratches and micro-chips of the blade. After such turning, the blade quickly dulls.
Pressure plays an important role... It is necessary to remember one simple rule: sharpness does not depend on the applied force, but on the duration of sharpening. Excessive pressure leads to chipping of microparticles from the blade and to poor-quality sharpening.
Wrong angle selection... The angle can vary - depending on the steel grade and the purpose of the tool. For household kitchen knives, it is 20 - 25 degrees. For other types of blades that have to withstand heavy loads and work with hard materials, the angle will be 40 degrees.

Guided by simple, but at the same time, appropriate rules for sharpening, you can not only save time, but also not spoil the product.

Sharpener "House"

Not a bad tool for sharpening knives. Despite its simple design, the sharpener does its job well. This structure consists of a rectangular bar, the upper edge of which is made in the form of a gable roof. The angle of inclination of one face is 20 - 25 degrees, which is optimal. The product must be installed with a blade end-to-end against one of the roof ridges, then take an abrasive wheel or a block with emery and move along a horizontal line. This ensures a constant angle of inclination, which leads to an even sharpening of the blade.

There are also complex designs of a homemade grinding machine. For manufacturing, you will need the following materials:

A piece of board measuring 500x150x20 mm.
A threaded metal stud that will guide the bar.
M8 bolts and nuts and wood screws.
Retaining nuts or wing nuts.
Ordinary textolite or plexiglass, which will serve as a substrate for a knife and a kind of movable bed.
To attach the knife, you should take a neodymium magnet. The usual one will not work, since its downforce is quite small.

The board must be cleaned, processed, and then made into a rectangle. Another board should be made in a rectangular shape, which will serve as a rack or support. Its height should be such that the slope of the main board is equal to 20 degrees. You can fasten them together with wood screws. Then attach the resulting structure to the workbench or cut out the countertop in advance, to which one of the studs will be attached. After securely attaching the pin to the table top, you need to take a 200x100 block and make two holes in it: one for the main pin, on which the movable carriage with a sharpener will be attached, and the other for the pin, which is attached to the table top.

Now you can start assembling the carriage with the sharpener holder. On the pin that will hold the carriage, you need to make two clips of wood, plexiglass or metal. Drill holes in the clamps, put on the stud and fix on both sides with nuts. The carriage will rotate freely along its axis.

The next step will be to install a neodymium magnet on a previously prepared plate. It is necessary to make a longitudinal groove in it so that the tripod can be moved up and down. Drill a hole in the middle of the bed and insert a bolt and nut, which, in turn, will press the plate. At the end of the plate, you can simply glue a neodymium magnet to hold the knife.

The homemade device is ready to use. It can be used to sharpen chisels and planers.

It should be noted that sharpening is carried out without water, so abrasive paper or a circle will wear out a lot, but this option is quite suitable for sharpening knives and tools at home.

Home knife

If the farm has a sharpening machine, it will facilitate the process, but there is one circumstance. When sharpening on a machine, it is almost impossible to evenly press on the knife. Therefore, you can make a knife sharpener that will guide the blade and provide even pressure. The result is a simple but effective electric sharpener. For its manufacture, you will need the following components:

Bar.
Four bolts or four M8 threaded studs.
Four lambs.
Self-tapping screws for wood.

A guide is attached opposite the electric grinder, along which the slider will move. The guide itself can be attached to a workbench or a pre-made bed can be made. It must be mobile. To do this, you can cut a longitudinal groove in the bed and fix the tripod with two pins. Then take two bars, drill holes on the sides, insert the studs and tighten them with thumbs on both sides. The next step will be the mount on which the cutting product will lie. This can be done with small pieces of timber that should be attached to the sides of the moving carriage.

After that, you can start sharpening. Set the movable carriage to the required height and clamp it with the lambs. Move the tripod itself to the desired distance, securely fix and sharpen the product, moving the knife along the side guides.

LM sharpener

If in the future it is planned to engage in professional sharpening of tools in large quantities, then you can make a sharpener, which is called: Lansky-Metabo. Fixture drawings for sharpening knives with your own hands are as follows:

If the product is clamped in the clamps with the root part, then the sharpening angle will be the greatest. A knife with this angle can be used as a cleaver and for processing hard wood. You can also easily sharpen knives from a planer. Knife clamps can be made from a corner or wood. The disadvantages of this design are the complexity of assembly and the large number of parts.

If it is not possible to assemble a complex tool for sharpening knives, then you can get by with improvised means and make manual knife sharpeners. A simple sharpener can be made from a corner frame with a whetstone mounted on it.

If the sharpener is supplemented with a sliding carriage, then you do not have to hold the knife at a certain angle, which, in turn, will have a good effect on sharpening the blade. To make a movable carriage, you will need a triangular bar and a magnet. It is best to use a neodymium magnet to pull the knife in and hold it securely. If there is no such magnet, then you can take the components from the HDD (hard disk).

Before you give a knife or other product for sharpening, you should familiarize yourself with the material that will help not only in making a sharpener with your own hands, but also save a certain amount. The main aspect is to gain additional experience, which will come in handy in the future.

Greetings, Samodelkins!
Today I want to show you how it is possible from the materials that are (or at least should be) in almost every workshop, make an excellent device for smooth sharpening of knives.

Initially, the master wanted to buy a ready-made knife sharpener in China (namely, in the Aliexpress online store), but he thought why not try to make such a sharpener himself with his own hands. Moreover, the prices for this product from Chinese friends are rather big.

For self-production, you will need the following materials and tools:
1. Ordinary board;
2. Sandpaper;
3. Screwdriver;
4. Hammer;
5. Thick electrode 1 pc;
6. Electric jigsaw;
7. A piece of laminate;
8. Bolts and nuts;
9. Wooden handle;
10. Hex key;
11. Fluoroplastic or textolite (fiberglass).

Let's get down to making the sharpener itself.
First, take an ordinary board and cut a piece out of it. Then it is necessary to process the resulting wooden blank, namely to grind it with sandpaper.

It will serve as the basis for our homemade grinder.
In terms of size, it turns out we have 26 cm in length, the workpiece is 6.5 cm in width, and the height of the wooden base is 2 cm.

It is also necessary to make holes in this board. In total, this part of the future product will have 6 through holes. We drill 2 holes for the stand itself (more on it later). Next we drill another hole of a smaller diameter, and also on the other side of the board we drill 3 more holes that will serve to fix the pressure plate.

Insert nuts into the holes made.

In the future, these nuts can be put on glue so that they do not fall out, but for now everything seems to be quite tight.
Then we will deal with the manufacture of the guide rack itself. Its master made from an ordinary thick electrode. It must be bent in half. Then, using a hammer, the author beat off the entire upper part from the welding electrode and grinded it. By the way, you can grind with an ordinary screwdriver. To do this, simply insert the electrode into the chuck of the screwdriver and, holding the sandpaper in your hand, grind the product.

At this stage, we insert the workpiece obtained from the electrode (guide post) into these two holes.
We do not insert at a right angle, but at a slight slope. The angle of the guide is anywhere from 65 to 70 degrees.

Everything sits down quite tightly, but also for greater reliability of our design, in the future it will be possible to put the guide post on epoxy glue, or on some other glue, or on something else.

But perhaps the master is mistaken and this is not fluoroplastic. Fluoroplastic is most often white and slippery of some kind. Most likely it is textolite or fiberglass. But in fact, this is not so important. The main thing is that this material is quite tough and does not wear off.
From this piece (PTFE or not PTFE), the author cut out a kind of pressure plate. He made holes in it, as well as small sweats, so that the hats go a little into the depth of the plate.

Then we put this plate on the wooden base made earlier. We fix it with screws.

The author took the cogs under a hex wrench. The master also made a small hole in the base of the future knife sharpener so that this key was always in this sharpener.

The whole thing is clamped and they (screws) are practically not visible on the plate.
But here, the master did not do the pot, since the sharpening part of the tool will not touch this screw.

Further, from the same fluoroplastic, the author made such a plate.

In this plate I made 2 holes for the same hex screw.
Further, the whole thing is put here and nestled with the help of a lamb.

Then the master made just such a guide for sharpening stones.

The length of the guide is 57 cm. Its author made it from a regular steel bar. I also cleaned it out. And on one end I put just such a handle (like from an old Soviet file).

You can also strengthen this connection by planting a wooden file handle on the glue, but here it has gone in quite tightly, nothing falls out.

Regarding the fastening of the sharpening stones themselves. The author took a small piece of the clamp, cut it off and made holes. As a result, we got such little corners, two identical.

And here I put a nut with a threaded thread and a clamping screw.

The master also put a spring on the guide so that you can change the sharpening stones without unscrewing the nut with a clamping screw.

The sharpening stones themselves, or rather the base for these stones, were made by the author from an ordinary piece of laminate. Just by cutting it into strips.

The width of the strips is 2.5 cm, and the length is about 20 cm.

On the pieces of the laminate there are already ready-made grooves, in fact, where the corners of the guide part of the device will become.
Then the author glued sandpaper to the pieces of laminate with double-sided tape and signed which one was where. And, in fact, this is how it all happened:

The whole thing is put quite easily. With the groove of the laminate we get into one corner of the guide, and with the second corner we press the whetstone with the help of a spring.

Everything. Nothing falls out anywhere. Everything lies flat and pretty tight.
Let's continue to collect our device further. We insert the guide with the sharpening stone fixed on it into the hole prepared in advance for it, and you can safely begin the process of sharpening the knife.

The stroke is quite large due to the fact that here the author has removed a small chamfer on both sides.

With repeated use of knives, each housewife is faced with a problem when they begin to dull and it becomes simply impossible to work with them. It is also unsafe as the knife can slip off when cutting and injure you. To prevent this from happening, knives should be sharpened in a timely manner using a special sharpening device.

You can buy a knife sharpener at your local hardware store or at the market that offers different types of devices. You will have to choose yourself. But, in order not to be mistaken, you need to know how to properly evaluate them in terms of convenience and quality of operation.

The proposed options do not always suit consumers, so many make sharpeners with their own hands, using special stones, tools and drawing sketches with dimensions. The photo shows options for homemade knife sharpeners.

Features of sharpening knives

When sharpening knives, the main thing is to make the correct angle of contact between the edges of the blades so that they serve you for a long time and efficiently. Therefore, when sharpening the knives yourself, it is necessary to maintain the existing angle of inclination of the blades.

Each knife blade has its own optimal tilt angles:

10 to 15 degrees - for a medical scalpel or straight razor;
from 15 to 20 degrees - for household knives used for cutting bread, vegetables or fruits;
from 20 to 25 degrees - for multifunctional knives for cutting a variety of products;
from 25 to 30 degrees - for reliable companions of hunters and tourists on long trips;
from 30 to 40 degrees - for cutting materials that are particularly hard.

To sharpen the correct angle of the blade, you cannot do without special tools, since it is difficult to do it manually.

The design of such devices is not complicated, so it is easy and quick to make it yourself, and detailed instructions for making sharpeners can be borrowed from the Internet.

Types of knife sharpeners

From a rather large assortment of various types of knife sharpeners, choosing the right option for yourself is quite simple.

The main elements of the sharpening device are a stop for fixing the knife and an abrasive bar, which are used as ready-made abrasive materials (stones) or of our own production. But before getting to work, you need to find out how to make a knife sharpener correctly with your own hands.

Varieties of stones for sharpening

There are several types of whetstones:

aquatic. Sharpening stones used in water are less worn out during use.
oil. In structure and configuration, they are similar to those of water, but with a more oily surface.
natural. For their manufacture, only natural raw materials are used with preliminary processing during the production process.
artificial. In this case, the name speaks for itself, that is, the abrasive material is created artificially.
rubber. They are not encountered as often as the previous ones, moreover, they are inconvenient in the process of application.

What can you make a sharpener for sharpening

To make a sharpening block with your own hands, you can use the simplest way. Take a small rectangular glass plate about 5 mm thick. Using double-sided tape, place coarse and medium-grit strips of sandpaper on both sides.

The bar is ready for use, if necessary, the worn out sandpaper can be easily replaced with a new one. This method is the most cost effective.

The disadvantages of this device include:

rapid wear of the abrasive and the fragility of the product (when fixing the bar, you need to be careful that the glass does not crack).
possible overheating of the material during fast movements during sharpening.

You can find the best knife sharpener ideas on their respective websites.

Bars made of wood

This method of making a tool for sharpening knives is also simple and accessible to everyone. You will need four identical blocks: two abrasive and two wooden.

At the beginning of work, sand the wood blocks with sandpaper so that their surface becomes smooth without burrs. Mark the bar in accordance with the required angle of inclination. Use a whetstone and mark its width on a block of wood.

Note!

Make cuts with a depth of 1.5 cm along the basting and insert the abrasives into the grooves. Secure the stones with bolts. A piece of rubber attached to the bottom will give the structure stability.

In addition, you can make an adjustable sharpener with your own hands, but the next article will tell you how to do this.

Photo of do-it-yourself knife sharpeners

Note!